Would You Bet $100,000,000 on D?

[Dmitry Olshansky]

On 20.09.2011 2:27, Don wrote:
> On 17.09.2011 19:58, Peter Alexander wrote:
>> On 17/09/11 4:32 PM, Adam D. Ruppe wrote:
>>> Peter Alexander wrote:
>>>> In contrast, my D hobby project at only a few thousand lines of code
>>>> already takes 11s to build and doesn't do any fancy metaprogramming
>>>> or use CTFE.
>>>
>>> Curious, did you use a library like QtD?
>>
>> Nope.
>>
>> I use some parts of the standard library, not much of it though. I also
>> use Derelict, but again, not much of it.
>>
>> I'm talking about a -release -inline -O build btw.
>>
>> For a normal build it's only 1.7 seconds.
>
> I have a suspicion about what's causing this. The main loop of the
> optimiser has a O(n^^2) behaviour with consecutive comma expressions.
> -release -inline makes a large number of comma expressions (there
> doesn't need to be any in your code). I've seen n reach 200; maybe it
> gets even higher in your case.
> This isn't an intrinsic O(n^^2) algorithm, it would be pretty easy to
> fix, I think.
>
>

I have no solid facts to confirm this but I also noticed that 
combination of -O and -inline on my code does take few times longer to 
build then two builds with each of flags used separately.


-- 
Dmitry Olshansky